As a packaging material for packaging various articles such as food, medicine, medical products and miscellaneous goods, a packaging bag provided with a zipper tape has been used, in which a pair of belt-like zipper tapes respectively including a male member and a female member that are engaged with each other is disposed on an opening of the bag, the zipper tapes being engageable and disengageable with each other.
Such a packaging bag provided with a zipper tape is sealed by sealing the opening. The packaging bag provided with the zipper tape is openable by removing a seal portion in a manner to tear a base material film of a bag body from a notch, cut-off or the like formed on both lateral sides of the packaging bag.
When opening the packaging bag, the base material film may be cut off near the zipper tape, so that a holding portion of the bag body for disengaging the engagement of the zipper tape may not be secured and an opening operation may be complicated. Accordingly, a technology for tearing the base material film at a predetermined position has been demanded (see Patent Literature 1).
A zipper tape disclosed in Patent Literature 1 includes a cutting portion at a longitudinal end of each of a male member and a female member. The cutting portion includes a first projecting portion, a second projecting portion and a thin portion that is provided between the first and second projecting portions and is thinner than the first and second projecting portions. With this arrangement, the thin portion is torn for opening, so that the holding portion of the bag for disengaging the engagement of the zipper tape is sufficiently secured.